Mark, Jasper and Lily are high school friends now in their early twenties. Mark is gay, living with Lily (his high school girlfriend), while Jasper is straight and soon to be married. A cynical and bitter trio barely connected by their past friendship, they reunite for the annual public Halloween celebration in San Francisco's Castro district. When the huge crowds of costumed revelers fail to entertain them, they begin a quest to find an elusive acquaintance who might provide them with some ecstasy.
This quest is interwoven with an abstracted remembrance of a high school camping trip the three friends took to the Lost Coast, a lush wilderness in northern California, during which Mark and Jasper were involved in a sexual relationship that Mark never got over, and Jasper never acknowledged.
Over the course of their evening in San Francisco the three are forced to confront this past, which has held them all in suspended animation. The Lost Coast explores the complexities of sexuality, repression, and isolation, with a quiet, measured style.